Fat Man

15

Kill the draug.

You can pick up this achievement at the end of Chapter 2. After breaking the curse, you will fight as a series of undead soldiers. The final fight puts you up against the Draug.

You can defeat the Draug by trapping him with Yrden. He will resist a couple of Yrden efforts, but once he gets stuck you are free to take him out. Repeat the process to win. Once the Draug dies, the achievement will unlock.